Questions regarding FAV

[pmbrunelle]

I would be interested in using an Aquamist FAV, but not a complete Aquamist system.

Thus, I have some questions regarding use of the valve.

Car specs:
1985 Pontiac Fiero 3.2L V6
turbo, non-intercooled
MegaSquirt 2 programmable fuel injection (controlling the FAV directly)
Injection 5" from the intake valves, via 6 check-valved nozzles
Pressurized water/methanol tank (compressed air) (not sure I trust those diaphragm pumps)



From the FAV web page, it says: "Always use 99% methanol". Is it acceptable to use the FAV with water?

With regards to hydrocarbons, is the FAV really that sensitive? If I am drilling/tapping the water/methanol reservoir, will even cutting fluid residues damage the FAV?

How do I choose between the 1300 cc and 1600 cc FAV for my application? What are the differences?

I have read this thread: http://www.aquamist.co.uk/forum2/vbu...ead.php?t=2922
what limits the PWM frequency to 30 Hz?
I was thinking of controlling the FAV like a standard port injector; one pulse per two crankshaft revolutions.
However, with a 6000 RPM redline, the valve would be working at 50 Hz.
Is the opening time a limiting factor? If I use a peak-and-hold driver, can I reduce the opening time?
Can I clamp to a voltage higher than 75 V to close the FAV faster?

Is the speed of the FAV influenced by the supply pressure?



...and not really FAV-specific, but more generally regarding water injection:
From the HFS3-v3.1 page, I saw the following recommendation:
"100% water: 10-15% water/fuel ratio or 0-5-1cc per BHP"

From NACA Report 756
Low octance fuel: tested up to 1.5 water/fuel with good results
High octane fuel: tested up to 0.6 water/fuel with good results

Why do you recommend such low water flow compared to Report 756?